This invention relates to steam humidification systems for supplying steam into heating and air conditioning systems or for other industrial uses of steam. More particularly, this invention pertains to steam humidification systems useful in situations where it is undesirable for any of the steam introduced into an airstream to condense onto any surface, but rather it is required that the steam be quickly assimilated into a passing air flow by vaporization of any gas-borne condensate.
Steam humidification systems are commonly used to raise the humidity level in air flow ducts. Typical untreated air in the winter months has very low absolute humidity, and it is desirable to increase the level of humidity in commercial and industrial facilities. This is particularly true for health care facilities such as hospitals and nursing homes. High relative humidity is also needed in industrial locations where static electricity is especially undesirable, such as in facilities housing electronic equipment, and in other industrial locations, such as fabric or paper handling, where a material must be prevented from drying out.
Steam humidification systems typically use dispersion tubes that are supplied with and dispense steam. Usually the dispersion tubes are positioned within air handling systems such as heating, ventilating and air conditioning (xe2x80x9cHVACxe2x80x9d) ducts to discharge steam into the air flowing through the ducts. The dispersion tubes may contain nozzles with which to dispense the steam. Since the steam is warmer than the air flowing through the HVAC ducts, the air flow in the ducts has a cooling effect on the dispersion tubes, and as the steam enters the dispersion tubes, some of the steam is cooled to the extent that it condenses into water. This is to be avoided because the gas-borne condensate, or water, can be discharged along with the steam. The result is water in the HVAC duct and other equipment, thereby providing an environment ripe for the growth of undesirable microorganisms.
Another known system for the humidification of a flow of air is the use of an array or bank of unjacketed dispersion tubes that are enhanced with various features to prevent condensed water from being discharged from the discharge orifices along with the steam. In such a system, the discharge orifices may have tiny tubes that extend into the dispersion tube to prevent condensed water from easily exiting the dispersion tube along with the flow of humidification steam.
Humidification systems frequently employ a valve to selectively control the flow of steam through the dispersion tubes. The valve is opened in response to the sensed humidity. Conventional valves generally do not have a mechanism built in to allow for drainage of liquid that can collect in the valve as the steam cools and condenses when the valve is closed. Conventional valves are thus subject to undesirable water collection. The valves can also cool during periods of decreased steam demand, as less steam passes through the valve to warm the valve. The valves typically have a large mass and may cool due to a heat transfer to its surrounding environment, thereby causing condensation of steam. It would thus be desirable to provide a smaller valve and a humidification system that provides for less cooling of the valve and water collection in the valve.
The above objects as well as other objects not specifically enumerated are achieved by a steam humidification apparatus having a dispersion tube having a jacket defining a jacket area. The steam humidification apparatus includes a steam line for supplying steam to the jacket. The steam humidification apparatus includes a valve having a seat, the valve being positioned to deliver dry steam to the dispersion tube. The steam humidification apparatus includes a separator in communication with the valve, the separator being mounted to receive steam and to deliver dry steam to the valve. The separator, the valve, and the dispersion tube are all positioned generally coaxial.
According to this invention, there is provided a steam humidification apparatus including a valve body having a lower surface, a seat, and a steam inlet. The steam inlet is positioned on the lower surface to receive steam through the lower surface of the valve body. The steam humidification apparatus includes a separator in communication with the steam inlet of the valve body. The separator is positioned to receive steam and to deliver dry steam to the steam inlet in the lower surface of the valve body. The steam humidification apparatus includes a plug movably disposed and adapted to be moved into and out of sealing engagement with the seat, and an operator operatively connected to the plug.